Transgenic Research最新文献

This study aimed to develop a reliable and efficient genetic transformation method for the ornamental Indian Lotus (Nelumbo nucifera Gaertn.) using the sonication-assisted Rhizobium radiobacter-mediated transformation technique. To conduct the transformation, shoot apical meristem explants were infected with Rhizobium radiobacter (synonym Agrobacterium tumefaciens) strain LBA 4404 containing a binary vector pBI121 that harbours the GUS reporter gene (uidA) and kanamycin resistance gene nptII for plant selection. To improve the transformation efficiency, we optimized parameters such as bacterial cell density, sonication duration, infection time, co-cultivation duration, acetosyringone concentration, cefotaxime, and kanamycin concentrations. Sonication treatment at 42 kHz for 90 s recorded the highest transformation efficiency. The selection of regenerated plantlets was performed on a kanamycin-supplemented selection medium. The putative transformants showed GUS expression in the leaves and petioles. The presence of the GUS gene was also confirmed in the putative transformants through PCR, with the appearance of the expected amplicon size of 520 bp. The presence of nptII was confirmed by PCR in the putatively transformed plants with an amplicon size of 530 bp. The maximum regeneration frequency obtained was 72.66%, and the highest transformation efficiency achieved was 9.0% in the Indian Lotus.

Bombyx mori nuclear polyhedrosis, caused by B. mori nucleopolyhedrovirus (BmNPV), threatens sericulture seriously. To explore strategies for controlling it, the UDP glycosyltransferase gene UGT41A3 (BmUGT41A3) was targeted. UGT is involved in exogenous substances detoxification and endogenous biomass regulation in insects. Early embryos of the BmNPV-sensitive variety 'HYB' were used to obtain the transgenic line HYB-UGT41A3, overexpressing BmUGT41A3 under the IE1 promoter. qPCR results revealed that, compared with the wild-type control 'HYB', BmUGT41A3 was upregulated during the individual developmental stages of HYB-UGT41A3 from silkworm eggs to fifth-instar larvae; peak expression was observed in the third-instar larvae, which presented the most significantly upregulated expression. Individual-tissues qPCR results revealed that BmUGT41A3 expression was highest in the hemocytes of HYB-UGT41A3, followed by the midgut, whereas expression in HYB was very low. Gradient feeding of BmNPV on HYB-UGT41A3 and control 'HYB' larvae on the first day of the second-instar stage. The results revealed that the LC₅₀ of HYB-UGT41A3 reached 4.040 × 10⁷ particles/mL, which was 20-fold greater than that of HYB. The decrease in the BmNPV load was more significant in HYB-UGT41A3 than in HYB at 48 h after viral inoculation. These results indicate BmUGT41A3 overexpression inhibits BmNPV proliferation and improve resistance to BmNPV in B. mori.

Eremopyrum triticeum is a typical spring ephemeral species, which in China mainly distributed in the desert regions of northern Xinjiang, and play an important role in the desert ecosystems. E. triticeum has several adaptive characteristics such as short growth rhythms, high photosynthetic efficiency, high seed production, drought and salt resistance. However, the molecular regulatory mechanism of E. triticeum in responses to abiotic stress resistance is still unknown. In this study, two NAC-like transcription factor-encoding genes, EtNAC1 and EtNAC2, were isolated from E. triticeum. The predicted EtNAC1 and EtNAC2 proteins possess a typical NAC DNA-binding domain at the N-terminal region. The qRT-PCR analysis showed that EtNAC1 and EtNAC2 were highly expressed in mature roots of E. triticeum, and were significantly up-regulated under drought, high salt and abscisic acid (ABA) stresses. Subcellular localization analysis in onion epidermal cells revealed that EtNAC1 and EtNAC2 were located in the nucleus. Expression of EtNAC1 and EtNAC2 in yeast cells improved the survival rate of yeast under low temperature, H₂O₂, high drought and salt stresses. Overexpression of EtNAC1 and EtNAC2 in Arabidopsis thaliana conferred enhanced tolerance to drought and salt stresses, increased ABA sensitivity, and transgenic plants showed higher proline (Pro) content, but lower malondialdehyde content, lower chlorophyll leaching, lower water loss rate and stomatal aperture (width/length) than WT plants. In conclusion, EtNAC1 and EtNAC2 play important roles in abiotic stress responses of E. triticeum, which might have significant potential in crop molecular breeding for abiotic stress tolerance.

Agrobacterium-mediated transformation of plants often results in the integration of multiple copies of T-DNA and backbone DNA from binary vectors into the host genome. However, the interplay between T-DNA and backbone DNA remains elusive. In this study, 70.8% of T₁ Arabidopsis transformants exhibited integration of both T-DNA and backbone DNA, and no cases of only backbone integration were observed. To elucidate the integration patterns, we employed bulk-genome resequencing in Arabidopsis and identified 20 integration sites across 10 T₁ transgenic plants, most of which were flanked by left borders of T-DNA at both ends. On average, each integration site contained 6.3 copies of T-DNA and 2.65 copies of backbone DNA. The junction structures between T-DNA and the backbone were highly variable, revealing a previously underappreciated frequency of readthrough at both the left and right borders. Transient expression studies in Nicotiana benthamiana leaves demonstrated that T-DNA and backbone DNA were simultaneously transferred into transformed cells, although the backbone DNA had lower copy numbers than T-DNA. These findings suggest a close relationship between T-DNA and backbone DNA during their transfer and integration, thus offering new insights into the mechanism underlying Agrobacterium-mediated transformation.

This viewpoint paper emphasises the need to diversify food production methods to simultaneously combat hunger and reduce environmental problems. The recommendations of the UN Food System Summit 2021 relate primarily to (i) the conservation of natural ecosystems, (ii) the sustainable management of existing agricultural land while increasing productivity and (iii) the restoration of already degraded land. Europe in particular faces unique challenges, such as reducing pollution and promoting organic farming up to 25 percent of the agricultural land area while maintaining food production. Ongoing efforts aim to create a transparent, fair and multi-level regulatory framework to support the Green Deal. The implementation of the Corporate Sustainability Reporting Directive (CSRD), which will sooner or later affect a larger proportion of European farmers, should support the transition. Science and innovation play a central role in this, as they are the cornerstones on which sustainable food systems are built. It is imperative that farmers actively participate in the co-design processes and utilise their wealth of experience and creativity to drive these innovations forward. A crucial aspect of the transition to sustainability is changing consumption patterns to limit food waste and reduce meat consumption. While this transition is essential, it is not without its formidable challenges. Diversification of agriculture, encompassing a spectrum of established techniques, is touted as a promising approach to achieving sustainability without sacrificing productivity. Furthermore, integrating truly sustainable agricultural practices with cutting-edge innovations, including new genomic techniques, has the potential to be a transformative solution.

In recent years there have been major advances in precision breeding technologies, such as gene editing, that offer promising solutions to revolutionise global crop production and tackle the pressing issues in food systems. The UK has leading expertise in genomics, and research is already taking place to develop crops with improved resilience to climate change, resistance to disease and less reliance on chemical inputs. In March 2023, the Genetic Technology (Precision Breeding) Act received Royal Assent and passed into UK law. It provides a framework from which to build more proportionate regulations for plants and animals made using genetic technologies which contain genetic changes that could also arise through traditional breeding-known as 'Precision Bred Organisms'. New legislation and the utilization of UK world-leading research could help to enhance the efficiency of breeding systems and enable the development of plants and animals that are healthier, better for the environment and more resilient to climate change.

In recent years, many strategies for sustainable food systems have been launched at the national and global levels, which require better tools to monitor their progress. Subsequently, discussions on their measurements have drawn enormous attention, and various indicators have been developed. As indicators at the national level reflect policy priorities in the respective countries, it is difficult to develop adequate global indicators that accommodate different national priorities. Additionally, if we pursue only the existing dataset, we may lose the thrust of the initial objectives. However, the collection of new data can place an enormous burden on stakeholders, both developing and developed countries. These difficulties were revealed in recent negotiations for the Kunming-Montreal Global Biodiversity Framework at the Convention on Biological Diversity at the 15th Conference of the Parties. Therefore, we must reach a compromise between what we want to achieve and the resources we can share.

Given the complexity of agricultural problems, it is essential to develop acceptable solutions for various stakeholders with diverse knowledge, viewpoints, and preferences. However, European public opinion has become highly polarized, making constructive discussions on these issues difficult. We present the results of the narrative analysis of media debate on new genomic techniques. The study identified two primary narrative groups: 'precaution-focused' and 'innovation-focused.' The former emphasizes caution, potential risks, and the need for stringent regulation, while the latter highlights benefits, progress, and the promise of genome editing for sustainable agricultural practices. Within each group of narratives, several distinct narratives were identified. The research has revealed that despite the high polarization, the narratives shared important values and beliefs. Going beyond the dividing narratives and concentrating on common values can depolarize the debate and set the stage for new narratives, enabling constructive debate, concentrating on solving problems, and maximizing collective outcomes.

Whether organisms developed with the use of genome editing techniques, or food derived from such organisms, are, or should be, regulated as genetically modified organisms (GMOs) or genetically modified (GM) food, respectively, remains a subject of debate globally. Much of the discussion has been scientific and focussed on the similar genetic outcomes of some genome editing techniques and 'conventional' or natural mutagenesis. Many jurisdictions, including Australia, have considered, or are considering, how their regulatory frameworks will deal with such organisms and products. In Australia, organisms developed with site directed nuclease 1 (SDN-1, with no added template to guide homology-directed repair) are not regulated as GMOs, pursuant to exclusions in the Gene Technology Regulations 2001. The exclusion of SDN-1 organisms from regulation in Australia is sometimes misrepresented, including in scientific peer reviewed publications, as extending to all genome edited organisms. This highlights the importance for researchers, developers and other stakeholders to understand that whether genome edited organisms are, or are not, subject to regulation as GMOs in a particular jurisdiction may quintessentially be a legal question, not a scientific one.